Consolidated average unit net cash costs (net of by-product credits) of $1.54 per pound of copper in fourth-quarter 2012 were lower than unit net cash costs of $1.57 per pound in fourth-quarter 2011 reflecting charges in fourth-quarter 2011 associated with new labor agreements and other employee costs, partly offset by higher fourth-quarter 2012 mining costs in North and South America.
FCX expects to gain access to higher grade ore at Grasberg in late 2013, which will result in higher copper and gold production volumes. Approximately 29 percent of 2013 consolidated copper sales volumes and 37 percent of consolidated gold sales volumes are expected in fourth-quarter 2013. Quarterly unit net cash costs vary with fluctuations in sales volumes and average realized prices for gold and molybdenum. Assuming average prices of $1,700 per ounce of gold and $11 per pound of molybdenum and achievement of current sales volume and cost estimates, consolidated unit net cash costs (net of by-product credits) for FCX's copper mining operations are expected to average $1.67 per pound of copper in first-quarter 2013 and $1.35 per pound for the year 2013. The impact of price changes on 2013 consolidated unit net cash costs would approximate $0.015 per pound for each $50 per ounce change in the average price of gold and $0.015 per pound for each $2 per pound change in the average price of molybdenum.
North America Copper Mines. FCX operates seven open-pit copper mines in North America - Morenci, Bagdad, Safford, Sierrita and Miami in Arizona, and Tyrone and Chino in New Mexico. All of the North America mining operations are wholly owned, except for Morenci. FCX records its 85 percent joint venture interest in Morenci using the proportionate consolidation method. In addition to copper, certain of FCX's North America copper mines (Sierrita, Bagdad, Morenci and Chino) also produce molybdenum concentrates.
Operating and Development Activities. FCX has completed projects to increase production at its North America copper mines, including restarting certain mining and milling operations and increasing mining rates at Morenci and Chino. Ramp up activities at Chino are continuing, with annual production of approximately 250 million pounds of copper targeted in 2014. FCX continues to evaluate opportunities to invest in additional production capacity at its North America copper mines in response to positive exploration results in recent years.At Morenci, FCX is engaged in a project to expand mining and milling capacity to process additional sulfide ores identified through exploratory drilling. The approximate $1.4 billion project is targeting incremental annual production of approximately 225 million pounds of copper in 2014 (an approximate 40 percent increase from 2012) through an increase in milling rates from 50,000 metric tons of ore per day to approximately 115,000 metric tons of ore per day and mining rates from 700,000 short tons per day to 900,000 short tons per day. Engineering activities are progressing and construction activities are under way.